Endoscope with sensor for image acquisition and tissue examination

Abstract

To provide an endoscope for medical examination and / or treatment of a human or animal body or tissue sections thereof.SOLUTION: An endoscope (10) that is configured for imaging as well as for tissue analysis is disclosed. For this purpose, the endoscope (10) comprises an image sensor to which multiple optical devices are arranged in order to carry out different tasks with one and the same image sensor, particularly the task of imaging and measurement tasks concurrently or temporally graded.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an endoscope for the medical examination and / or treatment of the human or animal body or tissue sections thereof. [Background technology]

[0002] Endoscopes are known for examining and treating a human or animal patient and include an elongated shank that can be inserted into the patient's body.

[0003] For example, US Pat. No. 5,999,366 discloses an endoscope with an optical device for spectrally examining tissue in front of the distal end of the endoscope. For this purpose, the endoscope is provided with a through hole at the distal end, which serves as a light entrance window. A variable filter can be acted on by a piezoelectric element so that the wavelength of the transmitted light can be modulated. Furthermore, an illumination device and an image capture device arranged in the housing of the endoscope are part of the endoscope. This endoscope therefore allows a spectral analysis of the captured light.

[0004] A method for texture determination based on spectroscopy is disclosed in US Pat. No. 5,399,633.

[0005] Furthermore, Non-Patent Document 1 discloses a small-sized spectroscopic measurement device.

[0006] Similarly, Non-Patent Document 2 discloses a spectroscopic measuring device.

[0007] Another construction type of a spectrometric measuring device is known from US Pat. No. 5,399,633.

[0008] A multifocal lens arrangement applied directly to an image sensor is known from US Pat. No. 5,399,633. This sensor is suitable for taking images of an object using different focal lengths simultaneously.

[0009] Patent document 5 discloses a miniature spectrometer having an electrical carrier plate on which a light source and a light collection element are arranged. The device is embedded in a transparent mass in which two lenses of different types are formed.

[0010] US Patent No. 6,399,633 discloses an endoscope having a working channel and a transparent end cap disposed at the distal end of the endoscope through which the surgical field can be illuminated by an LED light source. Furthermore, the end cap of the endoscope includes multiple optical components such as optical fibers or image sensors in addition to associated lenses.

[0011] US Patent No. 5,399,633 also discloses a system with multiple lenses, but these lenses are assigned multiple image sensors. The optical device can be part of a capsule that can be swallowed by the patient for examination of the digestive tract.

[0012] US Patent No. 5,399,633 discloses an endoscope having an optical device at its distal end for taking images from multiple directions and a rectangular image sensor at its proximal end, where images coming from different lenses are projected onto different zones of the image sensor.

[0013] US Pat. No. 5,399,633 discloses an authentication method and a fingerprint sensor adapted for this purpose. The fingerprint sensor comprises an optical window with a planar upper side for placing the finger and a back side with a sawtooth shape. The sawtooth shaped elements form a series of prisms. A light source can be used to illuminate the back side. In close proximity to the light source, a first lens is provided for generating an image on the CCD sensor and a second lens with a diffraction grating for imaging the spectrum of light reflected by the finger. The sensor comprises a first zone on which the image of the finger is projected and a second zone on which the spectrum is projected. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] European Patent Application Publication No. 2075617 [Patent Document 2] European Patent No. 2725967 [Patent Document 3] European Patent Application Publication No. 2284509 [Patent Document 4] International Publication No. 2018 / 072806 [Patent Document 5] European Patent No. 0939894 [Patent Document 6] International Publication No. 2010 / 129324 [Patent Document 7] US Patent Application Publication No. 2005 / 0154277 [Patent Document 8] US Patent Application Publication No. 2009 / 0147076 [Patent Document 9] US Patent Application Publication No. 2010 / 0141380 [Non-patent literature]

[0015] [Non-Patent Document 1] Andrea Toulouse, Johannes Drozella, Simon Thiele, Harald Giessen und Alois Herkommer, “3D-printed miniature spectrometer for the visible range with a 100 x 100 μm2 footprint”, [online], Internet:<URL:https: / / doi.org / 10.37188 / lam.2021.002> [Non-Patent Document 2] Yuhang Wan, Saoud A. Al-Mulla, Wang Peng, Kenneth D. Long, Benjamin A. Kesler, Patrick Su, John M. Dallesasse und Brian T. Cunnigham, “Integrated spectroscopic analysis system with low vertical height for measuring liquid or solid assays”, [online], Internet:<URL: http: / / www.elsevier.com / open-access / userlicense / 1.0 / > Summary of the Invention [Problem to be solved by the invention]

[0016] It is an object of the present invention to provide an endoscope that can be used for diagnostic purposes. [Means for solving the problem]

[0017] This object is achieved by an endoscope for medical examination and / or treatment of the human or animal body according to claim 1.

[0018] The endoscope according to the invention comprises at its distal end a light capture device and an illumination device. The light capture device comprises at least one imaging first optical device for capturing a video stream or even individual pictures. An image sensor, in particular in the form of a rectangular camera chip, is part of the light capture device. Image sensors in MOS or CMOS technology are particularly suitable.

[0019] The first optical device includes at least one optical element, for example an objective lens, which projects the camera image onto a first zone of the image sensor. The first zone of the image sensor is thus assigned to the first optical device. The zone can have an angular or in particular a rounded shape, for example a circular shape. The first zone is an image capture zone. The image sensor can in particular be a rectangular image sensor. Its aspect ratio can be, for example, 16:9. The first zone can also be rectangular, but can have a different aspect ratio, for example 4:3 or 1:1. The first zone can also have a shape different from a rectangular shape, for example polygonal or rounded.

[0020] Furthermore, the light capture device includes a second optical device to which a second zone of the image sensor is assigned. This second zone can be used for measurement purposes, thereby forming a measurement zone. The measurement zone and the first zone (imaging zone) are arranged adjacent to each other on the image sensor. They can have different shapes. The imaging zone can be, for example, rounded, while the measurement zone can be configured to be angular, in particular using an edge or corner area of ​​the image sensor.

[0021] Thus, the endoscope according to the invention comprises at its distal end a first optical device acting as an image acquisition device and a second optical device acting as a measuring device, both optical devices preferably having different light entrance windows and optical means arranged at said light entrance windows, for example objectives in the form of lenses, light passing gaps, optical gratings, optical filters, etc. An image sensor is commonly assigned to both optical devices, different zones of the image sensor being assigned to the first and second optical devices.

[0022] Both optical devices are preferably configured in such a way as to define respective optical axes, and more preferably, these two optical axes are oriented parallel to each other. Alternatively, the optical axes can be oriented in a converging distal direction, away from the distal end of the endoscope. By these measures, it is possible to align the imaging optical device and the measurement optical device with the same tissue region. In this way, for example, tissue defining the surgical region can be monitored while simultaneously measuring tissue properties.

[0023] The second optical device, which can be used for measurement purposes, can comprise two entrance windows spaced apart from one another, to which different second subzones of the image sensor are assigned. Preferably, the two entrance windows of the second optical device are arranged on one side of the first optical device, while the exit window of the assigned illumination device is arranged on the other side of the first optical device.

[0024] The light capture device may have a third optical device, to which at least one third zone on the image sensor is assigned, the third optical device being capable of performing a measurement task different from that of the second optical device.

[0025] The third optical device may include a respective light entrance window with a suitable objective lens or other optical means and may be configured for a desired measurement purpose, for example, the third optical device may be an apparatus for performing tissue examination.

[0026] The second and / or third optical device can perform diffuse reflectance spectroscopy. To perform the measurement, the distal end of the instrument, in particular the exit window, is brought into contact with the tissue. This allows the measurement of tissue located at different depths by subzones at different distances from the light source on the image sensor. The light source can be configured with a narrowband or broadband illumination method. The exit light can be entirely or partially in the visible light range or entirely or partially in the infrared light range. Information about the tissue layer from deeper tissue layers can be obtained.

[0027] The second and / or third optical devices may alternatively perform scattered light measurements, whereby a probe positioned away from the tissue illuminates tissue sections at different distances from the light source with different brightness, thereby allowing differential measurements of light scattered by the tissue, whereby light is emitted away from the tissue and different intensities may be measured at different distances from the light source depending on the degree of scattering at the surface.

[0028] The third optical device that can be used for measurement purposes can have two entrance windows spaced apart for this purpose, to which different third subzones of the image sensor are assigned. The two entrance windows of the third optical device are preferably arranged on two different sides of the first optical device. However, the exit window of the assigned illumination device is only arranged on one side of the first optical device. The two different third zones of the image sensor are arranged spaced apart from each other. For example, they can be arranged adjacent to opposite edges of a rectangular image sensor, respectively. Furthermore, the two entrance windows of the third optical device can be arranged at different distances from the exit window of the illumination device. This allows a differential measurement of tissue properties to be performed.

[0029] Further optical devices, to which further zones of the image sensor can be assigned, can be provided for further measurement methods. In particular, these further optical devices can perform microscopic or microscopic measurement methods. Alternatives are also possible. For example, the device can be configured for distance measurement or for further measurement tasks.

[0030] The illumination device includes at least one light source having a light output direction preferably substantially parallel to the optical axis of the first (imaging) optical device, which light source can be used for image capture and tissue measurement. It can be provided that the light source has a larger output angle than the imaging optics.

[0031] The light source may have a bandwidth, in relation to its light sensitivity, at least as large as the bandwidth of the image sensor. However, it is also possible to provide one or more light sources which only emit light with a bandwidth which is narrower than the sensitivity bandwidth of the image sensor and thus provides only a part of it. These light sources may be switched on and off depending on the measurement task, in order to accomplish different measurement tasks temporarily simultaneously or successively. The light sources may in particular emit visible light and infrared light. This spectral range may be provided by a single light source or may be allocated among several light sources.

[0032] The imaging zone is preferably arranged between two measuring zones, which are assigned to the second optical device, for example. The second optical device can be configured as a spectrometer. Likewise, if necessary, a third optical device can be provided, which is a spectrometer or even a differential optical measuring device. The different optical devices have different spatial arrangements or even configurations with respect to spectral sensitivity, so that they can be used to solve different measurement tasks. For example, the third optical device can perform diffuse reflectance spectroscopy. For this purpose of spectral filtering, the third optical device can include several filters arranged next to each other or filters with position-dependent colors that spectrally filter the received light, for example in the wavelength range from 600 nm to 900 nm. Those filters used for this purpose can be applied directly to the image sensor. Alternatively, one or more diffractive optical elements, such as prisms or gratings, can be arranged remote from the sensor.

[0033] In addition, the illumination device can have elements for structured illumination of the tissue, for example in the form of a light grating or another pattern. For this purpose, the illumination device can include a laser diode, in particular an infrared laser diode, to which a diffractive optical element is assigned for projecting the light pattern onto the tissue. If this occurs in the infrared range, the light pattern is invisible to the user. However, a 3D model of the tissue surface can be generated in this way.

[0034] It is also possible to assign two different optical devices to the same zone of the image sensor. For example, the imaging zone (first zone) of the sensor can be used simultaneously for imaging with visible light and for 3D modeling with infrared structured light. Also, other areas of the image sensor can be used in multiple ways.

[0035] The image sensor is preferably an RGB-IR sensor. Such a sensor comprises photosensitive elements (pixels) distributed over its rectangular photosensitive surface and arranged in a grid. Thereby, photosensitive elements for blue, green, red and infrared light are preferably distributed alternately in an appropriate manner over the surface of the sensor. For this purpose, the actual image sensor can be pre-provided by the manufacturer with a color filter array (Bayer array) for color display. The arrangement of the individual photosensitive elements is preferably identical in all zones of the image sensor, i.e. the imaging zone and the measurement zone. The color filter array can extend over a first zone that can be used for imaging and a second or third zone that can be used for measurement purposes. Alternatively, the color filter array can be omitted in the second and / or third zone or, if provided by the manufacturer, can be subsequently removed.

[0036] An image sensor can contain pixels that are sensitive to two, three, four or even more different wavelengths of light (meaning colors), and thus can analyze light with their respective spectral resolution. Thus, an image sensor with pixels that are sensitive to four different colors can distinguish between four different spectral lines (meaning light components) of the received light.

[0037] Furthermore, with the same image sensor it is possible to detect a significantly larger number of spectral lines than the number of colors that the image sensor itself can distinguish. This can be done in particular by using a multi-bandpass filter that passes light with different colors (meaning light in different wavelength ranges) and absorbs or reflects the rest of the light. Two or more multi-bandpass filters that distinguish each other in terms of color can be used, and these are preferably arranged directly adjacent to each other in the light path or next to each other at a distance, for example directly on the image sensor, so as to cover a larger group of pixels.

[0038] The different color components of the light passed through the multi-bandpass filter are equally incident on the different color pixels of the image sensor, which are sensitive (sensitivity regions) to different, for example four, wavelength regions (color regions). The sensitivity regions may overlap. For this reason, it is possible that a passing light of a single color activates two pixel types that are adjacent to each other in terms of wavelength of the image sensor. It is also possible that more than one pass region of the multi-bandpass filter is provided in one sensitivity region of an image sensor type. In the case of the presence of several pass regions of the multi-bandpass filter in the same sensitivity region, it is particularly easy to assign the light received by pixels of the same type to different spectral lines by calculation, if the pass region of the same multi-bandpass filter is present only once in the sensitivity region and not in adjacent overlapping sensitivity regions.

[0039] Further details of advantageous embodiments and details of the invention can be derived from the drawings, the description and the claims. [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a schematic diagram of an endoscope according to the present invention. [Diagram 2] FIG. 2 is a schematic front view of the endoscope according to FIG. [Diagram 3] FIG. 3 is a schematic top view of an image sensor and an illumination device in the endoscope according to FIGS. [Figure 4] FIG. 4 is a diagram of a pixel array of an image sensor in an endoscope. [Diagram 5] FIG. 5 shows the optical conditions during tissue examination with the tip of the endoscope placed against the tissue. [Figure 6] FIG. 6 is a diagram of an endoscope in use for imaging at a distance from tissue. [Figure 7] FIG. 7 is a diagram of an image sensor in an endoscope according to FIGS. 1 and 3 having image zones and filters for forming a multichannel spectrometer. [Figure 8] FIG. 8 is a diagram of the image sensor of FIG. 7 without the filter. [Figure 9] FIG. 9 is a first diagram for explaining the pass region of the first filter and the sensitivity region of the image sensor. [Figure 10] FIG. 10 is a second diagram for explaining the pass region of the second filter and the sensitivity region of the image sensor. [Figure 11] FIG. 11 is a diagram for explaining spectral lines detectable by an image sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] In Fig. 1, a schematic view of an endoscope 10 according to the invention is shown. The endoscope 10 comprises a distal end 11, which is inserted into a patient, e.g. into a body cavity of the patient, during the performance of an operation. The endoscope is then controlled from its proximal end 12, which may be provided with one or more control elements 13. Depending on the configuration of the endoscope 10, such control elements 13 can be used, for example, to move, in particular to bend, parts of the distal end 11. Apart from the distal end 11, the elongated shank 14 of the endoscope can be rigid or, if required, flexible.

[0042] The endoscope can have one or more working channels 15 that extend to a face 16 of the shank 14, which can be planar or dome-shaped. The one or more working channels 15 serve to position within the working channel a tool for affecting biological tissue, as well as a probe or instrument (not shown). Such an instrument can be, for example, a radiofrequency surgical instrument, a cryosurgical instrument, or other tool suitable for affecting tissue.

[0043] The endoscope 10 according to the invention comprises an extensive optical arrangement 22, for the description of which reference is made to figures 2 to 6. This optical arrangement 22 is located in the distal end section 17 of the distal end 11 and is itself geometrically stable and therefore of a substantially cylindrical design, independent of whether the shank 14 is rigid or flexible. However, the face part 16 can be domed and thus, for example, of a hemispherical design. Other shapes are also possible, in particular a substantially planar design with a rounded transition section to a cylindrical periphery, which may be convenient for certain measurement tasks as described below.

[0044] The part of the optical arrangement arranged in the end section 17 is firstly an illumination device 18 which comprises at least one, but possibly several, for example two or three, light sources 19, 20, 21 shown in Fig. 2 by means of exit windows. The light sources 19, 20, 21 can be light sources with the same optical properties, but in particular also light sources with different properties. The differences can concern:

[0045] - Bandwidth and / or - the spectral composition of the emitted light, - spatial distribution of light, e.g. for -Opening angle or - the generated light pattern or further -Temporal characteristics, e.g. -Continuous light, - Intermittent light and -The time when each light source is activated.

[0046] For example, the first light source 19 can be a light source for the red-infrared wavelength range, for example 600 nm-900 nm. The second light source 20 can be, for example, a white light source for the wavelength range of visible light, or even a light source of colored light in the visible range. Furthermore, the second light source can be a light source having at least partly the visible light range and at least partly the infrared range. Furthermore, the second light source can be a purely infrared light source. The light source 21 can be a white light source. The light source 21 can uniformly illuminate the surgical area. Alternatively, the light source 21 can only illuminate a sub-area. In particular, the light source 21 can be configured as a projection device and can generate an image or a light pattern in order to project, for example, a line image, a check image or another still or moving image on the tissue located in front of the distal end 11 of the endoscope.

[0047] The light output directions (optical axes) of the light sources 19, 20, 21 can be coincident or even different. In a preferred embodiment, the light output direction of at least one of the three light sources 19, 20, 21 is coincident with the longitudinal direction of the shank 14. The light output directions of two or even all three light sources are preferably oriented parallel to each other. The opening angles of the light cones leaving the light sources 19, 20, 21 can be of similar or even different dimensions. Thereby, one or more of the light sources 19, 20, 21 can each have a conical light output mouth with a circular light output surface. One or more of the light sources 19, 20, 21 can also define a light output surface that deviates from a circle, for example an elliptical, semicircular or rectangular light output surface.

[0048] The illumination device 18 is part of a sensor device suitable for taking images and performing tissue measurements, which in addition to the illumination device 18 comprises a light capture device 22. The light capture device 22 comprises an image sensor 23, which is shown separately in FIG. 3. The image sensor 23 can be a so-called camera chip with a number of light-sensitive cells (so-called pixels) arranged in a defined raster. The individual pixels are typically sensitive to different light colors, for example blue, green and red. In a preferred embodiment, there is additionally an infrared-sensitive pixel. The pixels in FIG. 4 are therefore characterized by "B" for blue light, "G" for green light, "R" for red light and "IR" for infrared light. This is an RGB-IR sensor.

[0049] A number of optical devices 24 , 25 , 26 are assigned to the image sensor 23 , which are shown in FIG. 2 based on their light entrance windows arranged in the face part 16 .

[0050] The first optical device 24 is an imaging device. It comprises an objective lens 27, represented by a lens 28 in Figs. 5 and 6. However, the objective lens 27 may comprise other and / or additional optical elements. The objective lens 27 is an imaging objective lens and projects an object image onto a first zone 29 of the image sensor 23. This zone 29 may have a shape that deviates from the periphery of the image sensor 23, as shown in Fig. 3, and may in particular be round, square or rectangular, for example with an aspect ratio of 4:3. The zone 29 is preferably located approximately centrally on the image sensor 23.

[0051] Between the short side 30 of the image sensor 23 and the zone 29, a second zone 31 acting as a measurement zone can be provided. This second zone 31 can be divided into a number of subzones, for example two subzones 311 and 312, arranged between the first zone 29 and the short side 30. The first zone 29 is an imaging zone, whereas the second zone 31 is a measurement zone.

[0052] At least one of the light sources 19, 20, 21 is assigned to the first optical device 24. For example, the light source 21 can serve to emit light to illuminate the tissue surface 32 (FIG. 6), and then the first optical device 24 serves to capture the respective image. However, the same or another light source, for example the light source 19, can be assigned to the second optical device 25. The light source 19 (or 20 or 21) is arranged on one side of a center line E passing through the first optical device 24 and the working channel 15, and the optical device 25 is preferably arranged on the other side of this line E. The device 25 can include one or two light entrance windows 251, 252 arranged next to each other, which receive light and direct it to the subzones 311, 312 of the image sensor 23.

[0053] Another possible arrangement of the light source, e.g. light source 20, and the light entrance windows 261, 262 of the third optical device is shown in Figures 2 and 3. A third zone 33 of the image sensor 23 is assigned to the light entrance windows 261, 262 of the third optical device 26, which third zone 33 can comprise two subzones 331, 332. The two subzones 331, 332 are preferably arranged on either side of the imaging zone 29. Thus, measurement zones or sections thereof 331, 332 are provided on either side of the imaging zone 29.

[0054] Furthermore, the remaining section of the image sensor 23 can be provided with a fourth measurement zone 34 which is likewise assigned an individual objective lens 35, which can be used, for example, for microscopy.

[0055] The rectangular image sensor 23 is therefore provided with at least one zone 29 which can be used for imaging and at least one additional zone which can be used for measuring tissue properties, preferably several additional zones 31, 33, 34. The imaging zone 29 is preferably arranged symmetrically, i.e. centrally, on the image sensor 23, whereas the zones 31, 33, 34 of the image sensor 23 which are suitable for performing measurement tasks can be arranged symmetrically or asymmetrically on either side of the imaging zone 29.

[0056] The image sensor 23 is preferably a semiconductor sensor having a plurality of pixels having the same uniform configuration for the imaging zone 29 and the measurement zones 31, 33, .

[0057] The endoscope 10 thus far described can be used in a variety of ways.

[0058] 6 shows a schematic representation of the endoscope 10 or its end section 17 in use for imaging. The endoscope 10 or its end section 17 is arranged away from a surface portion 32. The surface portion 32 is illuminated by a third light source 21. The tissue image is projected via an objective lens 27 onto the image sensor 23, in particular onto the imaging zone 29 therein. The image sensor 23 thus generates an image or video stream which can be transmitted, further by means not shown, to the proximal end of the endoscope 12 and from there towards an image display device, e.g. VR glasses, a screen or the like.

[0059] If the light source 21 is a light source for structured illumination or can be switched to emit structured light, the light source 21 can be used to project a light pattern onto the tissue surface 32. The resulting image can be fed to an image processor, which calculates from the image a 3D model of the tissue surface 32 and provides it for rendering.

[0060] It is also possible for the light source 21 to be configured to emit unstructured light in the visible light range and structured light in the infrared (non-visible) light range. In this way, the image sensor 23 can generate, on the one hand, an optical image for display to the surgeon and, on the other hand, an infrared image from which the image processing device can determine a relief image, i.e. a 3D model of the tissue surface 32, and provide it for further processing or observation.

[0061] FIG. 5 shows an operating mode in which no imaging is performed, but tissue measurements are performed. For this purpose, the distal face 16 of the endoscope 10 is applied to the tissue surface 32. The operation is described by way of example of a light source 20 cooperating with two parts 261, 262 of the optical device 26. For example, the light source 20 emits broadband infrared light that enters the tissue and is scattered there. The light reaches the entrance windows of the two parts 261, 262 via paths W1, W2 of different lengths. Since path W2 is longer, the subzone 331 receives light signals scattered in deeper tissue layers further from the surface. By comparing the two signals, it is thus possible to determine the scattering by the tissue, the type of tissue layer illuminated, and thus also the proximity to the organ. This applies in particular when organs located in the tissue have different light scattering properties than the surrounding tissues embedded therein. Furthermore, light is absorbed to different degrees at different wavelengths of light. If the tissue type present has a homogenous structure, it is even possible to distinguish between scattering and absorption by spatial differential measurements.

[0062] Alternatively, a source of infrared light, preferably of a less narrow band, or visible colored or white light, or light including parts of the visible and infrared spectral regions, can be provided to perform this differential diffuse reflectance spectroscopy.

[0063] At least one of the zones 31, 33 available for measurement purposes or at least one of their subzones 311, 312, 331, 332 can perform spectroscopic measurement tasks. For this purpose, in the individual zones 31 and / or 32 available for measurement, spectral filtering elements can be applied or arranged in relation to said zones. In the simplest case, narrow-band color filters 333, 334 (FIG. 5), for example interference optical filters, are applied directly to the image sensor 23, and each individual pixel or group of pixels is provided with one filter for a selected wavelength. In this way, a spectral analysis of the light backscattered from the tissue surface 32 can be performed simultaneously with the imaging. Instead of placing individual filters next to each other, so-called linearly variable filters can also be provided, the passing wavelength of which varies along a line, preferably a straight line.

[0064] By using the endoscope 10 according to the invention, different measurement tasks can be performed simultaneously or successively. When the endoscope 10 is positioned with its face away from the tissue surface 23, it can perform the following:

[0065] Imaging by the first optical device 24 - 2D imaging using visible light and simultaneous 3D detection using structured illumination using IR light, Imaging by an optical device 24 and differential diffuse reflectance spectroscopy using a third optical device 26; imaging by means of an optical device 24 and microscopy by means of a fourth optical device 35, Imaging with an optical device 24, diffuse reflectance spectroscopy with a third optical device 26 and microscopy with a fourth optical device 35.

[0066] However, when the endoscope 10 is placed with its face in contact with the tissue surface 23, the following can be done:

[0067] - Diffuse reflectance spectroscopy with a second optical device 25, and / or Diffuse reflectance spectroscopy with a third optical device 26.

[0068] As mentioned above, the zones of the image sensor 23 that are not used for imaging, other than the imaging zone 29, can be used for measurement purposes, thereby making it possible to carry out spectroscopic measurements by means of the image sensor 23. A particularly advantageous possibility of this is disclosed in figures 7 to 11, in which at least one of the measurement zones 31, 33, 34 is used as a spectrometer, thereby being configured as a spectrometer that is particularly suitable for the analysis of diffuse light.

[0069] The image sensor 23 comprises a number of pixels B (blue), G (green), R (red), IR (infrared) that are sensitive to different wavelength regions. The pixels can be arranged according to the scheme of FIG. 4 or in another scheme. Furthermore, the image sensor 23 can also have a different number of pixel types, for example only two or three pixel types. The sensitivity areas of the individual pixels B, G, R, IR are shown in FIGS. 9 and 10. As can be seen, every sensitivity area has a maximum value, whereby the light sensitivity of each pixel B, G, R, IR decreases on both sides of the maximum value. The sensitivity areas of adjacent pixels B / G, G / R can overlap significantly, as shown in FIGS. 9 and 10.

[0070] The two filters F1, F2, which are not arranged so as to overlap, are part of the spectroscopic measurement zone 34. The filters F1, F2 can be arranged on the image sensor 23 directly adjacent to each other or even at a certain distance from each other. The filter F1 is a first multi-bandpass filter which passes light within passbands a, d, e and h, as shown in an idealized way in FIG. 9, but absorbs or reflects light of other wavelengths. FIG. 10 shows the pass characteristic of the second multi-bandpass filter F2, which passes light within passbands b, c, f and g, as shown in an idealized way, but blocks, absorbs or reflects other wavelength regions.

[0071] Now, for the evaluation of the light, there are two groups of pixels, namely a group of pixels B, G, R, IR illuminated by the light of the multi-bandpass filter F1 and a second group with pixels B, G, R, IR illuminated by the light of the multi-bandpass filter F2. As is evident from FIG. 9, light of the passband e, for example, can thereby induce signals in the pixels G and R of the group under the filter F1. Similarly, light of the passband c can induce signals in the pixels B, G of the group under the filter F2. Although both light of the passbands d and e activate the pixel G with green sensitivity and light of the passbands b, c activate the pixel B with blue sensitivity, the spectral components of the passbands d, e as well as those of the passbands b, c can be separated from one another. This is explained below by way of example of the intensity I of the spectral components of the passbands c and e, respectively, present in the overlapping region. The separation of the spectral components of the passbands d and e of the filter F1 is particularly simple, since in addition to the passband e within the overlapping area, there is only one single passband d adjacent to it. Moreover, there is no passband of the same filter F1 in one of the adjacent sensitivity areas of the pixels G and R, and no passband is present in the other of the adjacent sensitivity areas of the pixels G and R. The passband F is assigned to the second filter F2, where it can be read out without bias by the red pixels R.

[0072] Similarly, light in passbands b and c under filter F2 actuates both pixels B and G. However, only for pixel B there is an additional passband b. However, the green pixel G only receives light in passband c, while light in passband d is available through the pixels of the first filter region F1.

[0073] The intensity I of the passbands c and e can be determined as follows:

[0074] The relationship between the signal of pixel B and the signal of pixel G in the overlap region at wavelengths in the passband c is known from the data sheet, where F between GB at c The signal G provided by the green pixel G for the passband c is at c B at cTo obtain the strength of between GB at c Multiply by the signal or strength I c and I b can be calculated as follows:

[0075]

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[0081] This results in a spectrum with eight spectral lines as shown in FIG. 11. Additional surface areas of the image sensor 23 can be provided with additional multi-bandpass filters in order to further improve the spectral resolution. The condition for this is that the ratio of the spectral sensitivities of adjacent pixels with respect to wavelength is known in the overlapping areas and that there is only one multi-bandpass double occupancy per channel (RGB). These double occupancies are d and e in FIG. 9 and b and c in FIG. 10. It is useful if at least one of the same filters in adjacent color channels (here R and G) or the respective other filters has no channel occupancy (pass area of ​​the respective filter).

[0082] The invention relates to an endoscope 10 that is configured for imaging and tissue analysis. For this purpose, the endoscope 10 comprises an image sensor 32 on which a number of optical devices 24, 25, 26 are arranged in order to perform different tasks, in particular imaging and measuring tasks, simultaneously or stepwise in time with the same image sensor 23. [Explanation of symbols]

[0083] 10 Endoscopy 11 Distal end of endoscope 10 12 Proximal end of endoscope 10 13 Operational elements of the endoscope 10 14 Shank of endoscope 10 15 Working channel of endoscope 10 16 Face of shank 14 17 End Section 18 Lighting Equipment 19 1st light source 20 Second light source 21 Third light source 22 Light capture device 23 Image Sensor R Red-sensitive pixel G Green-sensitive pixel B Blue-sensitive pixel IR Infrared Sensitive Pixel 24 1st optical device 25 Second optical device 251, 252 Part of the second optical device 26 Third optical device 261, 262 Part of the third optical device 27 Objective lens of optical device 24 28 Objective Lens 27 Lens 29 1st Zone (imaging zone) 30 Short side 31 Second Zone (Measurement Zone) 311, 312 Subzone of Zone 2 31 32 Tissue surface 33 Third Zone (Measurement Zone) 331, 332 Subzone of Zone 31 333, 334 Color Filter F1 First multi-bandpass filter F2 2nd multi-bandpass filter a~h Passbands of filters F1 and F2 34 4th Zone (Measurement Zone) 35 Objective Lens

Claims

1. An endoscope (10) for medical examination and / or treatment of the human or animal body, comprising: an elongated shank (14) including an illumination device (18) and a light capture device (22) at a distal end (11); The light capture device (22) includes at least an imaging first optical device (24) and a second optical device (25) to which a first zone (29) and a second zone (31) of the image sensor (23) are assigned to define an imaging zone (29) on a common image sensor (23) and at least one measurement zone (31) different from the imaging zone (29). Endoscope.

2. The first optical device (24) and the second optical device (25) each define an optical axis. The endoscope according to claim 1 .

3. These two optical axes are defined parallel to each other. The endoscope according to claim 2.

4. The light capture device (22) includes a third optical device (26) to which at least one third zone (33) on the image sensor (23) is assigned, the at least one third zone (33) forming a separate measurement zone different from the imaging zone (29). The endoscope according to any one of claims 1 to 3.

5. The second optical device (25) includes two light entrance windows (251, 252) to which different second zones (311, 312) of the image sensor (23) are assigned. The endoscope according to any one of claims 1 to 3.

6. The two light entrance windows (251, 252) are arranged at different distances from the lighting device (18). The endoscope according to claim 5.

7. The illumination device (18) comprises at least one light source (19, 20, 21) having a light output direction (A2) defined to be parallel to the optical axis (A1) of the first optical device (24), the illumination device (18) comprising at least one light source (21) arranged at a lateral distance from the first optical device (24). The endoscope according to any one of claims 1 to 3.

8. The imaging zone (29) is disposed between two measurement zones (31 / 34; 331, 332). The endoscope according to any one of claims 1 to 3.

9. The second optical device (25) performs spectroscopic measurements and / or differential optical measurements. The endoscope according to claim 1 .

10. The second optical device (25) is arranged with respect to the first optical device (24) using sub-areas (251, 252) that are asymmetrically arranged on the image sensor (23) and / or the third optical device (26) is arranged with respect to the first optical device (24) using sub-areas (261, 262) that are symmetrically arranged on the image sensor (23). The endoscope according to claim 1 .

11. At least two color filters (333, 334, F1, F2) matching different wavelengths are applied to the image sensor (23) to form a spectrometer. The endoscope according to claim 9 or 10.

12. The image sensor (23) preferably comprises a plurality of pixels (R, G, B, IR) sensitive to different wavelength regions arranged in a periodic pattern, and the at least two color filters (F1, F2) are multi-bandpass filters each having a plurality of passbands (a, d, e, h; b, c, f, g). The endoscope according to claim 11.

13. At least two of the wavelength regions of the different pixels (R, G, B, IR) overlap with each other, and light having wavelengths in the overlapping regions generates signals in both pixels that are sensitive to the overlapping regions. The endoscope according to claim 12.

14. At least one of the multi-bandpass filters (F1, F2) includes at least one passband (e, c) provided between adjacent wavelength regions of each of the pixels (R, G, B, IR). The endoscope according to claim 12.

15. The at least two color filters (F1, F2) configured as a multi-bandpass filter are arranged so as to cover a group of a plurality of pixels (R, G, B, IR) having high sensitivity to different wavelength regions, and each group includes a plurality of pixels (R, G, B, IR) in each wavelength region. The endoscope according to claim 12.

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